Creeping wart cress

Lepidium coronopus, the creeping wart cress or swine cress (Coronopus squamatus), is a low, sprawling annual or biennial herb of the Brassicaceae family native to temperate Europe, North Africa, and western Asia and naturalised on disturbed compacted ground across the temperate world. From a slender taproot it forms a flat basal rosette of deeply pinnately divided, dark green, strap-like leaves and produces prostrate, radiating stems five to thirty centimetres long. Tiny four-petalled white or faintly purplish flowers about two to four millimetres across are clustered in short, dense racemes opposite the leaves through summer. The characteristic fruit is a small, kidney-shaped, two-celled silicle four millimetres across, conspicuously wrinkled and warty on the surface, splitting at maturity into two one-seeded segments. The plant favours hard-trodden ground, farmyards, paths, and field margins.